Telephone system.



NO- 830,271. PATENTED SEPT. 4, 1906.

1). 1;. WILSON. TELEPHONE SYSTEM. APPLICATION FILED JAN. 2, 1996.

sagas DAYED H. WILSON, OF CHICAGO, ILLINOIS, ASSIGNOR TO ROBERT BINES OF CHICAGO, ILLINOIS.

TELEPHONE SYSTEM.

Bio. 8230,2171.

Specification of Letters Patent.

Patented Sept. a, 1906;

Application filed January 52,1906. Serial Ho. 294,250.

, terns, and has for its object to provide a new and improved system of this descri tion.

This invention is illustrated in t e accompanying drawings, wherein Figure 1 is a diagrammatic view showing one construction embodying the invention.

Fi 2 is a view showing the instrument at 011?. end of the line as operated on a grounded circuit.

As is well known, one of the difliculties encountered in telephone systems is the disturbance due to induction on the line. One of the objects of the present invention is to obviate the evils due to this cause.

As shown herein, there are provided a set of instruments at each end of the line comprising a transmitter A, a receiver B, and an induction-coil O. The induction-coil has two cores D and E. The core D has a primary coil D and a secondar coil D while the core E has a primary. coi E and a secondary coil E The primary coils D E are connected in multiple and are in circuit with the transmitter A and the source of current-supply A.

The secondary coils D E are connected in series in the main line F, leading to the instruments at the distant station. Between the cores D and E is a core G, containing a sme'ie coil G, connected in circuitwith the receiver B and without a battery or other sourceof current-supply. I

it will be seen that t e receiver is electrically independent of both the rimary and secondary circuits and is in a circuit having 1 electrical connection with the transmitteruit or the main line over which the meso be received is transmitted. It will be seen that the coil in the receiveris wound upon a core by itself and :ing no other coil. re D has pole-pieces H, core G has pieces I, and core E has pole-pieces J. sole-pieces of the various cores are preferably magnetically insulated from each other as shown by the insulating-pieces L.

It will be seen that in the construction of Fig. 1 the receiver-coil is on a core magnetic- I ally separated from the core of the primary and secondary coils.

In operating the device the operator talking into the transmitter causes a current to out on the line in the ordinary manner.

TVhen the current reaches the receiving-station, it acts upon the cores D and E, so as to energize them, and they in turn energize the core G.

The variations in the current due to the action of the transmitter at the other end cause a variation in the magnetic circuit of the cores D and E, and this variation afl'ects core G so as to induce a talking-current in coil G,

which is transmitted into s eech by the're- 7o ceiver B free from any and a external induction eifects'in the main line.

By means of this construction the rattling and other disagreeable noises produced in the receiver by induction on the line are obviated,

and messages may be sent for longer distances than islpossible when the inductive effects are present. Y

Itwill be seen that in this construction the receiver is in a circuit which is cut off conductive1y,.both electrically and magnetically, from the main line over which the talkingcurrent is transmitted.

I claim- 1-. A telephone system comprising a primary and a secondary circuit wound upon a core, a receiver-circuit electrically independ ent of the primary and secondary circuits and wound about a core located in proximity to said first-mentioned core so as to be influ- 9o enced thereby.

. A telephone system comprising a trans mitter-circuit and a line-circuit, a portion of each of said circuits being wound about a core, a receiver-circuit, a core therefor about which a portion of said circuit is wound, said latter core in proximity to the core about which a portion of the transmitter and line circuits are wound, but magnetically insulated therefrom. v

3.' A telephone system c mprising a transmitter-circuit containing a transmitter and a source'of current-supply, a line-"circuit leading to the distant station, two iron cores about which'a portion of each of said circuits is wound, an intermediate iron core, a receiver-circuit electrically independent of the other two circuits and having aportion wound about said intermediate core.

4. A telephone system comprising a transmitter-circuit containing a transmitter and a source of current-supply, a line-circuit leading to the distant station, two iron cores about which a portion of each of said'circuits is wound, an intermediate iron core, a re ceiver-circuit electrically-independent of the other two circuits and having a portion Wound about said intermediate core, said several cores being magnetically insulated from each other.

5. A telephone system comprising a transmitter-clrcuit containing a transmitter and a source of current-supply, a line-circuit leading to the distant station, two ion cores about which a portion of each of said circuits is wound, the windings of the transmittercircuit on the two cores being connected in multiple and the windings of the main-line circuit being connected in series, an intermediate iron core, a-receiver-circuit electrically independent of the other two circuits and having a portion wound about said intermediate core.

DAVID H. WILSON.

Witnesses:

. DONALD M. CARTER, EDWARD T. WRAY. 

